Edit Distance (Leetcode 72)

Problem Link: https://leetcode.com/problems/edit-distance/

class Solution:
    def minDistance(self, word1: str, word2: str) -> int:
        
        m=len(word1)
        n=len(word2)
        dp=[[0 for i in range(n+1)] for j in range(m+1)]
        for i in range(m+1):
            for j in range(n+1):
                if(i==0 and j==0):
                    dp[i][j]=0
                elif(i==0):
                    dp[i][j]=j
                elif(j==0):
                    dp[i][j]=i
                else:
                    if(word1[i-1]==word2[j-1]):
                        dp[i][j]=0+dp[i-1][j-1]
                    else:
                        insert=1+dp[i][j-1]
                        delete=1+dp[i-1][j]
                        replace=1+dp[i-1][j-1]
                        dp[i][j]=min(min(insert,delete),replace)
        return dp[m][n]